Some embodiments relate to the recovery of hydrocarbons from subterranean formations. In some cases, they relate to methods of using electro-osmotic coupling effects to improve fracture clean-up to increase the rate and/or amount of hydrocarbon that flows to producing wells.
Hydrocarbons (gas, condensate, and oil) are typically found in the pores of subterranean rock formations. Although occasionally hydrocarbons flow naturally to a producing well at a commercially acceptable rate and extent due to inherent hydraulic forces, normally some means must be employed to increase the rate and/or extent of this flow. Methods include pumping and enhanced recovery, which will not be discussed further, and stimulation. Stimulation methods increase or improve the flow path from the reservoir to the producing well. They include acidizing, fracturing, fracturing and gravel packing in a single step (frac-packing) and acid fracturing. In most cases, stimulation involves injecting into a formation a fluid that, if left in place, would hinder the subsequent flow of fluids (injection fluids or fluids to be produced). Therefore, fluids used in stimulation treatments are typically produced back, that is removed back through the well through which they were injected. However, for a variety of reasons, in hydraulic fracturing this clean-up is usually difficult and incomplete. A method of improving hydraulic fracturing fluid clean-up is needed.